At 02:30 hrs on 2 October 2014, a loaded coal train derailed at Porthkerry, between Barry and Rhoose on the Vale of Glamorgan line in South Wales. The last two wagons in the train were derailed when the rail beneath them collapsed. Nobody was injured.
The cause of the derailment was the failure of a section of the left-hand rail due to a metallurgical defect within that rail. The defect arose due to impurities within the steel which had been present since manufacture. The rail had been installed at Porthkerry in 2008 but had previously been used at another site. The presence of the defect was not discovered when the rail was installed at Porthkerry.
The rail was not replaced before it collapsed due to a combination of factors: visual inspections intended to identify this type of defect had not been carried out, the regular track inspections had not found it and none of the staff responsible for management of the track had identified that the rail needed urgent replacement.
The defect that was later to cause the derailment was eventually discovered on 30 July 2014 during an inspection that was being carried out to monitor a different type of rail defect. However, according to Network Rail’s standards, a defect of the type identified did not require urgent attention and therefore a period of 52 weeks was allowed for rail replacement. Consequently no action was taken to address the reported defect before the date of the derailment.
RAIB has made three recommendations to Network Rail concerning the methods used to detect this type of rail defect, the techniques used to assess its severity and assessing the risk posed by similar rail in other locations.
RAIB has also identified a learning point for the industry concerning the delegation of inspections by track maintenance engineers.
Response to recommendations:
- RAIB will periodically update the status of recommendations as reported to us by the relevant safety authority or public body
- RAIB may add comment, particularly if we have concerns regarding these responses.